Greetings new help live in vegas my 07 trx400 new only mods k & n filter with closed lid, I have pilot 42, air and screw is turn 2 and quarter turns, stock main 148. It’s smoking and can’t get it to idle. Only will run with thorttle pressed and choke in off position please help
Honda trx400 carb jet settings
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At this point it cant be jetting thats causing this. What needs to be done is check the pilot orifice at the bottom of the carb bore. Its not letting fuel through it for what ever reason. Thats why you have to give it throttle so it can take the fuel from the needle valve and the other small orifices in the bottom of the carb bore. The throttle plate when all the way closed should leave one small hole on the engine side. This is where your pilot screw and pilot jet allow fuel to be pulled out of it via the vacuum from the engine. If that hole is clogged you will never get an idle. So the idle screw could be turned out to far causing the throttle plate to cover it. Or it could be clogged with something that was in the carb bowl. It is a very very small hole. Makes it very very easy to clog.
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Is this the sport model or 4x4? The 4x4 has a TPS on it & may have to be relearned if you had it off.
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The orifice im talking about is in the bore of the carb. But the mixture screw would be the other end of that path in the carb.
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The bore is the round tube going from one end to the other. One side goes into the engine intake boot. And other side goes to the airbox.
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I too have a quick question I'm new here haven't learned how to start my own thread but my question is my 2002 Honda 400EX has a power bomb FMF header with a DG slip-on and I was wondering if anybody knows what to Jet the carburetor at because I can't find a straight answer anywhere and because my bike is not running right it will idle all day long you can play with the throttle rev It Up kind of sputters and then when you go to take off it starts to dies out brand new carburetor so I figured I have to jet it to match the pipes I bought the bike this way wasn't running for the other guy either
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42 pilot jet for sure. And main jet depends on alot of things. Your altitude your ambient air temp and where you ride are all factors. Thats why you havent found a straight answer. Becuase honestly there isnt one. There is a rule of thumb that each mod is around 2 steps up on main jet each. It also depends if your running airbix lid on or off or modified. Pretty much we need absolutely every last bit of information to get you even in the ball park. But to me the problems your having dont sound like just jetting. They will run and ride no problem with way wrong jets. May not last very long before they blow the motor but they will be able to ride them no problem until it pops. My .02 Welcome to the forums! (P.S. If you tell me which layout your using for the forum site i can guide you to the proper way to start a thread.)
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